<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>2</title>
</head>
<body>
<!--1.prompt("请输入姓名"):用户交互 2.document.write(s):html文本打印-->
    <script>
      let s = prompt("请输入姓名");
      document.write(s)
    </script>
</body>
</html>